I am a guy who wants to mount an original switch. And if one is acting bad it is wise to replace them all.

The switches the guy used in his vid are the most crappy ones to get, they can give a vibrating contact. If that is not damped by (most common) a capacitor then it will be very anoying.

No, switches are not polarity sensitive but they do come in several configurations. Most common is switching on, but there is also switching off, switching over (3 pin switch) and as a push-hold and moment switch.

Lucky tactile switches are for 99% only simple moment switches, switching on when pushed and fall open when letting go..